Unveiling the violent universe (1950–1970), Part 2. The rise of relativistic astrophysics and the new astronomies in the Soviet world

Abstract In the previous paper, we have outlined the systematic interconnections that, between the 1950s and 1960s, Iron Curtain notwithstanding, prepared a unitary framework for the exploration of the “violent universe”, thanks to the emergence of new astronomies (radio, gamma, X-ray) and the rise of relativistic astrophysics. In this paper, we will zoom-in on a Soviet event, the nature of which is not entirely clear, that took place in Tartu in the summer of 1962. Calling attention to it will not only allow us to fill a historiographical gap (since the premonitions of relativistic and neutrino astrophysics that were discussed have eluded the historians’ attention), but also to highlight important elements of its broader context and focus on some significant personalities who were present there. In this way, we will further show how the conceptual links that we have previously traced were indeed embedded in the technological scenario of the Cold War, shaped by the arms race and the space race. Once these aspects are clarified, we will expand on three versatile personalities who, in different ways, embodied the flowing together of new physical, astronomical, and cosmological developments: I.S. Shklovsky, B.M. Pontecorvo and, perhaps more than anyone else, one of the former leaders of the Soviet H-bomb project, Ya.B. Zel’dovich. Starting from the period of the Tartu event, Zel’dovich put his military work to the side (but exapting new technological possibilities from that) and led one of the world’s most important groups in the newly born relativistic astrophysics, with all its implications and interconnections with fundamental physics. By sketching the outcomes of the research of these scientists around the year of the Tartu event and then throughout the 1960s, we will also be able to outline the transition from the early “shared culture” (1950s-beginning of the 1960s) that we have been emphasizing to the unified perspectives that emerged in the following decades, up to multimessenger astronomy.